"Dave Plowman" wrote in message

In article ,
Arny Krueger wrote:
Here's the crimping tool of my dreams:

http://www.centralofficetools.com/in...D=32&do=detail

Wow. I like the bit about taking all standard dies, but is there a
standard?

I've seen dies that worked with different makes and models of crimpers. I
guess that would constitute a standard...

"Robert Morein" wrote in message

"Dave Plowman" wrote in message
...
In article ,
Arny Krueger wrote:
BTW, a good job of crimping amounts to cold welding with the extra
bonuses of high mechanical strength and inherent disruption of oxide
films or dirt on the connector or the wire. Given my choice, I'd
pick a well-crimped connection over the other two, but I would not
worry about a good job based on the other two methods. Crimping and
welding have the disadvantage of not being as field-repairable as
soldering.

The other beauty of crimping is that there is no weakening due to
heat close to the joint - perhaps not that important where the lead
is adequately clamped, though.

I don't understand your reasoning.
Electrical copper is, or should be, in a completely annealed state.
Heating the copper up isn't going to hurt it.

Heating disturbs the wire's plastic insulation, which provides a significant
amount of strength and resistance to sharp bends.

I have found, however, that soldered cable connections frequently
break from strain, even if they are correctly soldered.

A crimped connection typically includes some of the plastic insulation,
which strengthens the connection and helps avoid sharp bending near the
connection.

Connections
are frequently repaired over again, due to inadequate strain relief
on the center conductor that appears in large diameter coaxial cable.

Happens with small coax and non-coaxial cables, as well.

"Robert Morein" wrote in message

"Dave Plowman" wrote in message
...
In article ,
Arny Krueger wrote:
BTW, a good job of crimping amounts to cold welding with the extra
bonuses of high mechanical strength and inherent disruption of oxide
films or dirt on the connector or the wire. Given my choice, I'd
pick a well-crimped connection over the other two, but I would not
worry about a good job based on the other two methods. Crimping and
welding have the disadvantage of not being as field-repairable as
soldering.

The other beauty of crimping is that there is no weakening due to
heat close to the joint - perhaps not that important where the lead
is adequately clamped, though.

I don't understand your reasoning.
Electrical copper is, or should be, in a completely annealed state.
Heating the copper up isn't going to hurt it.

Heating disturbs the wire's plastic insulation, which provides a significant
amount of strength and resistance to sharp bends.

I have found, however, that soldered cable connections frequently
break from strain, even if they are correctly soldered.

A crimped connection typically includes some of the plastic insulation,
which strengthens the connection and helps avoid sharp bending near the
connection.

Connections
are frequently repaired over again, due to inadequate strain relief
on the center conductor that appears in large diameter coaxial cable.

Happens with small coax and non-coaxial cables, as well.

"Dave Plowman" wrote in message

In article ,
Robert Morein wrote:
I don't understand your reasoning. Electrical copper is, or should
be, in a completely annealed state. Heating the copper up isn't
going to hurt it.

Don't know the theory, but if you flex a wire close to a soldered
joint it will always break at the joint. Perhaps it's a chemical
reaction?

This happens with stranded wire because the stress tends to concentrate at
the point where the solder flow ends. I've pointed out other issues related
to insulation in another post.

[Thinks.] But don't you have to quench copper if annealing?

I don't think so. The usual rule is to quench to harden, and cool off slowly
to anneal.

"Dave Plowman" wrote in message

In article ,
Robert Morein wrote:
I don't understand your reasoning. Electrical copper is, or should
be, in a completely annealed state. Heating the copper up isn't
going to hurt it.

Don't know the theory, but if you flex a wire close to a soldered
joint it will always break at the joint. Perhaps it's a chemical
reaction?

This happens with stranded wire because the stress tends to concentrate at
the point where the solder flow ends. I've pointed out other issues related
to insulation in another post.

[Thinks.] But don't you have to quench copper if annealing?

I don't think so. The usual rule is to quench to harden, and cool off slowly
to anneal.

On Thu, 27 Nov 2003 07:01:38 -0500
"Arny Krueger" wrote:


Heating disturbs the wire's plastic insulation, which provides a
significant amount of strength and resistance to sharp bends.

Oh please, the last shred of insulation at the end of the wire provides
near zero additional strength, and besides:

1) The cable itself ought to be clamped before entering the strain
relief.
2) If you're melting the insulation you have either crap wire or no
soldering skill whatsoever.

I have *NEVER EVER* had the actual solder joint or copper wire near it
fail in any of the hundreds of leads I've made over the years. the only
failures I have ever had have been fracturing of the wire *after exiting
the strain relief*, and even then only after a good long service life.
(ok so the occasional one had a dry joint too, no-ones perfect)

--
Spyros lair: http://www.mnementh.co.uk/ |||| Maintainer: arm26 linux

Do not meddle in the affairs of Dragons, for you are tasty and good with
ketchup.

On Thu, 27 Nov 2003 07:01:38 -0500
"Arny Krueger" wrote:


Heating disturbs the wire's plastic insulation, which provides a
significant amount of strength and resistance to sharp bends.

Oh please, the last shred of insulation at the end of the wire provides
near zero additional strength, and besides:

1) The cable itself ought to be clamped before entering the strain
relief.
2) If you're melting the insulation you have either crap wire or no
soldering skill whatsoever.

I have *NEVER EVER* had the actual solder joint or copper wire near it
fail in any of the hundreds of leads I've made over the years. the only
failures I have ever had have been fracturing of the wire *after exiting
the strain relief*, and even then only after a good long service life.
(ok so the occasional one had a dry joint too, no-ones perfect)

--
Spyros lair: http://www.mnementh.co.uk/ |||| Maintainer: arm26 linux

Do not meddle in the affairs of Dragons, for you are tasty and good with
ketchup.

On Thu, 27 Nov 2003 08:53:08 -0500, "Arny Krueger"
wrote:

[Thinks.] But don't you have to quench copper if annealing?

I don't think so. The usual rule is to quench to harden, and cool off slowly
to anneal.

It works the other way round with metals like copper. The quick quench
leaves them soft and malleable, a slow cool will harden them.
Soldering to a really massy connector is the worst from this point of
view because it tends to hang on to the heat.

And the copper is not the only problem. Soldering a joint will tend to
overheat the insulation, leaving a slightly charred end. This is also
rather harder than the covering on the rest of the wire, and
concentrates the stress accordingly. A strain relief clamp at least
half an inch from the soldered connection is always a good idea.

Obviously a good soldering iron with plenty of thermal mass (coupled
with experience) will tend to get the joint completed before too much
metal has heated up. This results in as good a job as you can expect.

d

_____________________________

http://www.pearce.uk.com

On Thu, 27 Nov 2003 08:53:08 -0500, "Arny Krueger"
wrote:

[Thinks.] But don't you have to quench copper if annealing?

I don't think so. The usual rule is to quench to harden, and cool off slowly
to anneal.

It works the other way round with metals like copper. The quick quench
leaves them soft and malleable, a slow cool will harden them.
Soldering to a really massy connector is the worst from this point of
view because it tends to hang on to the heat.

And the copper is not the only problem. Soldering a joint will tend to
overheat the insulation, leaving a slightly charred end. This is also
rather harder than the covering on the rest of the wire, and
concentrates the stress accordingly. A strain relief clamp at least
half an inch from the soldered connection is always a good idea.

Obviously a good soldering iron with plenty of thermal mass (coupled
with experience) will tend to get the joint completed before too much
metal has heated up. This results in as good a job as you can expect.

d

_____________________________

http://www.pearce.uk.com

In article ,
Arny Krueger wrote:
Connections are frequently repaired over again, due to inadequate
strain relief on the center conductor that appears in large diameter
coaxial cable.

Happens with small coax and non-coaxial cables, as well.

I repair a lot of audio cables, and perhaps the most common is the thin
wire used for personal mics, which near always 'goes' just above the
connector. Sleeve it and it goes at the top of the sleeving. The cable is
often near impossible to replace completely as the mic is usually sealed,
so in practice it's best not to sleeve the connector cord grip at all, as
this involves shortening the cable more at the next repair.

--
*A cubicle is just a padded cell without a door.

Dave Plowman London SW 12
RIP Acorn